/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.mock.web;

import java.util.Collections;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import javax.servlet.ServletContext;

import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;

/**
 * Mock implementation of the
 * {@link org.springframework.web.multipart.MultipartHttpServletRequest} interface.
 *
 * <p>As of Spring 5.0, this set of mocks is designed on a Servlet 4.0 baseline.
 *
 * <p>Useful for testing application controllers that access multipart uploads.
 * {@link MockMultipartFile} can be used to populate these mock requests with files.
 *
 * @author Juergen Hoeller
 * @author Eric Crampton
 * @author Arjen Poutsma
 * @see MockMultipartFile
 * @since 2.0
 */
public class MockMultipartHttpServletRequest extends MockHttpServletRequest implements MultipartHttpServletRequest {

    private final MultiValueMap<String, MultipartFile> multipartFiles = new LinkedMultiValueMap<>();


    /**
     * Create a new {@code MockMultipartHttpServletRequest} with a default
     * {@link MockServletContext}.
     *
     * @see #MockMultipartHttpServletRequest(ServletContext)
     */
    public MockMultipartHttpServletRequest() {
        this(null);
    }

    /**
     * Create a new {@code MockMultipartHttpServletRequest} with the supplied {@link ServletContext}.
     *
     * @param servletContext the ServletContext that the request runs in
     *                       (may be {@code null} to use a default {@link MockServletContext})
     */
    public MockMultipartHttpServletRequest(@Nullable ServletContext servletContext) {
        super(servletContext);
        setMethod("POST");
        setContentType("multipart/form-data");
    }


    /**
     * Add a file to this request. The parameter name from the multipart
     * form is taken from the {@link MultipartFile#getName()}.
     *
     * @param file multipart file to be added
     */
    public void addFile(MultipartFile file) {
        Assert.notNull(file, "MultipartFile must not be null");
        this.multipartFiles.add(file.getName(), file);
    }

    @Override
    public Iterator<String> getFileNames() {
        return this.multipartFiles.keySet().iterator();
    }

    @Override
    public MultipartFile getFile(String name) {
        return this.multipartFiles.getFirst(name);
    }

    @Override
    public List<MultipartFile> getFiles(String name) {
        List<MultipartFile> multipartFiles = this.multipartFiles.get(name);
        if (multipartFiles != null) {
            return multipartFiles;
        } else {
            return Collections.emptyList();
        }
    }

    @Override
    public Map<String, MultipartFile> getFileMap() {
        return this.multipartFiles.toSingleValueMap();
    }

    @Override
    public MultiValueMap<String, MultipartFile> getMultiFileMap() {
        return new LinkedMultiValueMap<>(this.multipartFiles);
    }

    @Override
    public String getMultipartContentType(String paramOrFileName) {
        MultipartFile file = getFile(paramOrFileName);
        if (file != null) {
            return file.getContentType();
        } else {
            return null;
        }
    }

    @Override
    public HttpMethod getRequestMethod() {
        return HttpMethod.resolve(getMethod());
    }

    @Override
    public HttpHeaders getRequestHeaders() {
        HttpHeaders headers = new HttpHeaders();
        Enumeration<String> headerNames = getHeaderNames();
        while (headerNames.hasMoreElements()) {
            String headerName = headerNames.nextElement();
            headers.put(headerName, Collections.list(getHeaders(headerName)));
        }
        return headers;
    }

    @Override
    public HttpHeaders getMultipartHeaders(String paramOrFileName) {
        String contentType = getMultipartContentType(paramOrFileName);
        if (contentType != null) {
            HttpHeaders headers = new HttpHeaders();
            headers.add("Content-Type", contentType);
            return headers;
        } else {
            return null;
        }
    }

}
